Container with stackable base

ABSTRACT

A stackable, heat processable, blow molded, plastic container is disclosed. The container has a body that has top and bottom ends and a tubular sidewall. The container also has a dome with a finish having an opening. The dome is connected to the top end of the body and the finish is adapted to engage a first closure. Finally, the container has a base connected to the bottom end of the body. The base is contoured to engage at least a portion of a protrusion on a second closure, thus causing the two containers to be stackable.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a container having a stackable base and a complementary closure. More particularly, the invention is a base for a heat processable plastic container having a stacking ring to engage a complementary protrusion on a closure of a second container.

[0003] 2. Description of the Related Art

[0004] Known containers include bottles, jars, tubs and pails. Closures for such containers include screw caps and press-fit lids, and may be one structural piece or made of a plurality of structural component pieces, exclusive of sealing rings and/or liners. Such closures may include a raised peripheral ring around the top to provide improved strength. Ribbed closures are known and have a raised peripheral ring with vertical striations on the skirt to facilitate gripping by a user. Ribbed closures may be made as one piece structures or structures having a plurality of pieces. Closures may include protective liners and sealing means including but not limited to gaskets and liners.

[0005] One piece closure structures include screw caps and press-fit lids, and may be employed to close bottles, jars, tubs, and pails filled with foodstuffs and other consumer products. Two piece closure structures include screw caps and lids, and have an outer ring and an inner portion such as a disc. The outer ring may be threaded and generally has an upper flange in which the inner portion is seated. Examples of two piece closure structures include the well-known canning jar lid and vacuum sealable lids seated in ribbed rings. Complex closure structures include caps and lids and may additionally include valves and measuring means. An example of a complex closure is a laundry liquid container provided with a screw cap fitted with a press valve.

[0006] Known containers can be stacked but stability of the stacked containers is often inadequate because resistance to being tilted is poor.

[0007] Accordingly, it is an object of the present invention to provide a container, which can be stacked with similar or dissimilar containers to provide a stable stack having greater resistance to being tilted.

[0008] It is another object of the present invention to provide a method for improving stackability of a plurality of containers.

SUMMARY OF THE INVENTION

[0009] The above and other objects of the invention can be accomplished by an embodiment of a stackable, heat processable, blow molded, plastic container having a body that has top and bottom ends and a tubular sidewall. The container also has a dome with a finish having an opening. The dome is connected to the top end of the body and the finish is adapted to engage a first closure. The container has a base connected to the bottom end of the body. The base is contoured to engage a portion of a protrusion on a second closure.

[0010] In another embodiment, a stack of heat processable, blow molded, plastic containers includes a first container having a body with top and bottom ends and a tubular sidewall. The first container has a dome with a finish having an opening. The dome of the first container can be connected to the top end of the body. The first container also has a base connected to the bottom end of the body. The base is contoured to engage a portion of the protrusion of a second closure on the second container. The stack further includes the second container having a body having top and bottom ends and a tubular sidewall. The second container also has a dome connected to the top end of the body with a finish having an opening. The second container has a closure having a protrusion and being adapted to engage a finish of the second container, and a base connected to the bottom end of the body. The base of the first container has a stacking ring contoured to engage a portion of the protrusion of the closure of the second container. To be stackable, the stacking ring of the first container is adapted to engage the protrusion on the closure of the second container.

[0011] In yet another embodiment, a stackable, blow molded plastic container has a body, dome and base. One of the body, dome and base has a distortion resistant structural element that is capable of resisting distortion caused by subsequent hot-fill, retort, or pasteurization processes.

[0012] Yet another embodiment provides a method for manufacturing a plastic container adapted for use with filling processes which are conducted at elevated temperatures such as hot-fill processing, retort processing, pasteurization, and the like. The method includes the steps of providing a body, dome and base of the container. The base includes a stacking ring that is contoured to engage a closure of a second container.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 shows an exemplary embodiment of a stackable, heat processable, blow molded, plastic container according to the present invention;

[0014]FIG. 2 is a perspective view of an exemplary embodiment of a base of a plastic container according to the present invention;

[0015]FIG. 3 is a detailed view of an exemplary embodiment of a base of a plastic container according to the present invention;

[0016]FIG. 4 is a detailed view of an exemplary embodiment of a base of a plastic container according to the present invention;

[0017]FIG. 5 illustrates an exemplary embodiment of a stacking arrangement according to the present invention;

[0018]FIGS. 6A, 6B, 6C, 6D, and 6E are partial cross-sectional views showing alternative embodiments of container bottoms having bases with the stackable contoured structure of the invention mated with protrusions of a closure of a second container having contour variations in which:

[0019] the base shown in FIG. 6A has an indented angled cross-section mated with a protrusion shown as an angled protrusion;

[0020] the base shown in FIG. 6B has an indented rectangular cross-section mated with a protrusion shown as a rectilinear protrusion; and

[0021] the base shown in FIG. 6C has an indented frustoconical cross-section mated with a protrusion shown as a rectilinear protrusion;

[0022] the base shown in FIG. 6D has an indented triangular cross-section mated with a protrusion shown as a triangular protrusion;

[0023] the base shown in FIG. 6E has an indented semi-circular cross-section mated with a protrusion shown as a semi-circular protrusion;

[0024]FIG. 7 illustrates an exemplary embodiment of a stacking arrangement according to the present invention;

[0025]FIG. 8A shows an exemplary embodiment of a closure according to the present invention;

[0026]FIG. 8B shows an exemplary embodiment of a closure according to the present invention; and

[0027]FIG. 9 shows a perspective view of an exemplary embodiment of a plastic container according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0028] Heat processable, blow molded containers are designed to withstand the rigors of filling processes including without limitation: hot-fill processing, retort processing and pasteurization. The use of plastic, particularly blow molded polyethylene terephthalate (PET), in the manufacture of such containers has become commonplace and presents opportunities for creating unique design characteristics. However, design restrictions imposed to allow for heat-processing simultaneously presents particular challenges for achieving useful modifications. This is true with most of the other common materials used to make such plastic containers, for example polyolefins.

[0029] The hot-fill process is the procedure by which containers are filled with a beverage or some other liquid at a high temperature and capped soon thereafter. As the beverage or liquid cools within the container, stresses and strains develop in the container due to changes in the volume of the contents.

[0030] In retort processing, a container is filled at ambient temperature and capped, heated to high temperatures, for example, 260° F. at super-baric pressures (i.e., up to 45 psi) and then cooled back to ambient temperatures.

[0031] Pasteurization involves filling a container with a liquid or other substance that has an elevated temperature, for example, 140° F., and then raising the temperature to high temperatures, such as, 220° F. to 240° F. and then allowing the container and its contents to cool to ambient temperature.

[0032] Heat processable containers are subjected to varying internal pressures and volumetric changes (depending on the heat process used) due to higher processing temperatures, and therefore, expansion of the contained products and associated vapors. Without structural support, heat processing can cause plastic containers to distort in a commercially-unacceptable manner. Improved base construction can prevent the base of a plastic container from undergoing excessive outward deflection, i.e., deflection below the container standing ring.

[0033] These improved bases typically include, at least, a standing ring and a central concavity, known as a push-up, to prevent distortion. The presence of a standing ring and a push-up in the heat processable container may reduce the container's stackability because there is not a large surface area in the base of the container to make contact with another container. Stackability may be further reduced if the container has an upper end or closure or the like that also fails to provide a large surface area to mate with the base of another container. In that situation, the surface areas of the base and the upper portion of another container must align for the containers to stack.

[0034] In such an arrangement, although the containers are stackable, they are not likely to be capable of being tilted. To improve the tiltability of such a stack of containers, the base of the container, more particularly, the portion of the standing ring that mates with closure of another container can be contoured so as to straddle a closure of another container.

[0035] As used herein, the phrase straddle is intended to include essentially any straddling engagement, i.e., surface area engagement, since an engagement of even about 1% of the protrusion by the base is somewhat effective to improve stackability of such containers. In exemplary embodiments, the engagement is greater than about 50% of the protrusion and can be near 100%.

[0036] For example, in embodiments where a first container is a tubular jar and is stacked in mating engagement on a protrusion of round screw cap of a second container, the percent of straddling engagement, i.e., surface area engagement, would be determined as follows. In this example, the base of the tubular jar has the contour of an indented annular ring in a bottom view having inner and outer diameters and having the radial cross-section of a rectangle of 2 mm by 4 mm which is open on one of the 4 mm sides so as to straddle the peripheral rim of the screw cap. In this example, the protrusion of the screw cap has inner and outer diameters which are approximately equivalent to those of the indented annular ring contour of the base, has about a 4 mm difference between its outer and inner diameters, and is raised about 2 mm from a central flat portion of the screw cap. Thus, the percent of straddling engagement, i.e., surface area engagement, of the indented annular ring of such a base on such a protrusion would be approximately 100%, that is, a substantial mating engagement. In other exemplary embodiments, the indented annular ring in the container base and protrusion on the closure may have dimensions of about 2 mm×6 mm. Variations from substantial mating engagement may be due to (a) differences in the radial cross-sectional shapes of the base and the peripheral rim, (b) differences in respective diameters, (c) differences in the completeness with which the base covers the periphery of the protrusion; and (d) varying tolerances during the manufacturing process.

[0037] Referring now to the figures, FIG. 1 shows an exemplary embodiment of a stackable, heat processable, blow molded container 10 that can include a base 16 (and complementary closure) for improving the stackability and tiltability of a stack of containers. Container 10 can have a body 11 formed by sidewall 12. Body 11 can have a width W measured by the width of sidewall 12 at its widest point. Sidewall 12 can be tubular. As referred to herein, tubular means non-tapered and can include cross sections which may be substantially cylindrical, square, or other shapes. For example, as shown in FIG. 1, sidewall 12 is substantially cylindrical. As shown in FIG. 9, sidewall 12 can be substantially square. This and other exemplary embodiments can be shown in further detail in U.S. patent application Ser. No. 10/366,617, which is incorporated herein by reference in its entirety and is owned by the assignee of the present invention.

[0038] Sidewall 12 can include a pair of flex panels 73 a and 73 b (as shown in FIG. 7) that can be opposite one another in body 11 and each flex panel 73 a and 73 b can be planar. Sidewall 12 can also include a plurality of sidewall ribs 74 (as shown in FIG. 7). Sidewall ribs 74 can be horizontal or vertical (not shown). Particular embodiments of body 11 that include flex panels 73 a, 73 b and sidewall ribs 74 are shown in U.S. Pat. No. 6,439,413, which is incorporated herein by reference in its entirety and is owned by the assignee of the present invention.

[0039] Container 10 can also have a dome 13 that can merge with sidewall 12. Dome 13 can have a finish 14 that can define an opening 15 for filling and pouring the contents of container 10. Dome 13 can be a conventional dome, meaning dome 13 narrows sidewall 12 to finish 14. Finish 14 can be adapted to receive closure 50 (shown in FIG. 5) as discussed in detail below.

[0040] Container 10 can also have a base 16 that can be contoured so as to straddle closure 50 of another container as shown in FIGS. 5 and 7. As shown in FIG. 2, base 16 can have standing ring 20 for contact with a horizontal surface (not shown) on which the container can rest. Base 16 can also have bottom wall 26 that defines a central concavity 26 a known as a push-up. Stacking ring 23 can be interposed between standing ring 20 and bottom wall 26. Stacking ring 23 can be a continuous ring, but in another exemplary embodiment, stacking ring 23 need not be complete and may have gaps. In yet another embodiment, stacking ring 23 can have an incomplete radial cross-section because stacking ring 23 can adjoin flat portion 28 of labeling lug 29. As shown in FIG. 3, stacking ring 23 can have a diameter D₂ that extends across stacking ring 23 on center. In an exemplary embodiment, sidewall width W greater than stacking ring diameter D₂.

[0041] Standing ring 20 can have outer portion 21 that can merge base 16 with sidewall 12. Standing ring 20 can also have inner portion 22 that can merge with outer wall 24 of stacking ring 23. Stacking ring 23 can include inner wall 25 that can merge with bottom wall 26. In an exemplary embodiment, at least a portion of outer wall 24 and inner wall 25 can be vertical, i.e., substantially parallel to sidewall 12. Push-up 26 a can have a plurality of support ribs 27 extending radically from the central concavity. Support ribs 27 can have a base disposed upwardly into the central concavity and an apex disposed downwardly towards stacking ring 23.

[0042] As shown in FIG. 3, support ribs 27 can have a trapezoidal shape. In an alternative support ribs 27 can have a pyramidal shape. In yet an alternative exemplary embodiment, push-up 26 a does not include support ribs 27. This and other exemplary embodiments of base 16 are shown in U.S. patent application Ser. No. 10/366,574, which is incorporated herein by reference in its entirety and is owned by the assignee of the present invention.

[0043]FIG. 4 shows a detailed cross-section of stacking ring 23. In an exemplary embodiment, stacking ring 23 can be angled downward at an angle α from outer wall 25 to inner wall 24. Angle α can be between 1° and 15° from horizontal. More particularly, angle α can be approximately 7° from horizontal.

[0044] As shown in FIG. 5, stacking ring 23 can mate with protrusion 51 of closure 50 to provide the desired stackability and tiltability. Closure 50 can mate with stacking ring 23 by aligning protrusion 51 with stacking ring 23. In such a mating engagement, the stacking ring 23 of container 10 can straddle the protrusion 51 of closure 50. Specifically, standing ring 20 can surround peripheral wall 52 of closure 50. Closure 50 can have a diameter D₃ that is measured across the center of protrusion 51. In an exemplary embodiment, closure diameter D₃ is approximately equal to stacking ring diameter D₂.

[0045] In an exemplary embodiment, closure 50 can be one contiguous piece (as shown in FIG. 5), such as a press-fit or screw-on lid or the like, and protrusion 51 can form a peripheral ring around closure 50. In another exemplary embodiment, as shown in FIG. 8B, closure 50 can be a two-part closure. Closure 50 can have inner disc portion 82 and a ring 81. In this embodiment, protrusion 51 can be formed on ring 81. In another embodiment, as shown in FIG. 8A, protrusion 51 can be formed on inner disc portion 82. In either embodiment, ring 81 can have a substantially vertical skirt 84 with internal threads (not shown) to threadedly engage a finish of another container. Skirt 84 can have external vertical striations 83 to aid gripping.

[0046]FIGS. 6A, 6B, 6C, 6D and 6E are partial cross-sectional views showing alternative embodiments of container 10 having bases 16 with the stackable contoured structure of the invention mated with protrusions 51 of closure 50 having contour variations. Stacking ring 23 of base 16 shown in FIG. 6A has an intended angled cross-section mated with protrusion 51 shown as an angled protrusion. Stacking ring 23 of base 16 shown in FIG. 6B has an intended rectangular cross-section mated with protrusion 51 shown as a rectangular protrusion. Stacking ring 23 of base 16 shown in FIG. 6C has an indented frustoconical cross-section mated with protrusion 51 shown as a rectilinear protrusion. Stacking ring 23 of base 16 shown in FIG. 6D has an indented triangular cross-section mated with a protrusion 51 shown as a triangular protrusion. Stacking ring 23 of base 16 shown in FIG. 6E has an indented semi-circular cross-section mated with protrusion 51 shown as a semi-circular protrusion. As will be appreciated by persons skilled in the art, the configurations illustrated in FIGS. 6A-6E are non-limiting and other configurations can be used. Further, it will be appreciated that the objects of the invention can be achieved without the stacking ring 23 and protrusion 51 having identical shapes. For example, the rectangular protrusion 51 (FIG. 6B) can mate with an angled stacking ring 23 (FIG. 6A).

[0047]FIG. 7 shows an exemplary embodiment of a stack 70 of containers 71, 72 according to the present invention. Stack 70 can include top container 71 and bottom container 72. Top container 71 can include base 16 that is contoured, thus forming a stacking ring as described in FIGS. 2-6, to straddle a protrusion on closure 50 of bottom container 72, as described in any of FIGS. 5, 6 and 8. In the mating arrangement shown in FIG. 7, sidewall width W is greater than stacking ring diameter D₂ and stacking ring diameter D₂ is equal to closure diameter D₃, thus causing the top container to straddle the bottom container. This straddling has the effect of improving stackability and tiltability.

EXAMPLE

[0048] The significantly improved resistance to tilting of a stack of containers according to the present invention was demonstrated in the following tests conducted on containers, which were bottles fitted with two piece screw caps. The containers were equivalent except that the “control containers” did not have a base according to the present invention defined in their bottoms. The “stackable containers” according to the invention had bases as illustrated in FIGS. 2-5 and 6A.

[0049] A two-piece 63 mm ribbed closure was employed which included a plastic ring having a peripheral rim with a raised annular section with a 65.9 mm outer diameter and a 54 mm inner diameter, and a metal disk positioned within and retained by the ring. The raised annular section had a radial cross-sectional shape, which was generally rectangular and extended vertically above the plane of the metal disk by about 2 mm. The width of the longer leg of the rectangle was about 6 mm. Containers according to the invention which were provided with a base had a complementary radial cross-sectional shape and not only engaged and straddled the peripheral rim of the container below it in a stack but featured a mating engagement because of the complimentary shapes, dimensions, and diameters.

[0050] A plastic jar weighing 50 grams±1 gram and having an overflow volume of 705 cc±20 cc was modified to have a stackable base according to the invention, i.e., “stackable container”. Unmodified jars provided the “control containers”. Water weighing 686 grams at ambient temperature was filled into both types of containers.

[0051] The empty and water-filled containers were stacked 2, 3, or 4 high on a horizontal surface and each stack's resistance to being tilted was tested by tilting the surface in a controlled manner. Table 1, which follows gives the degree from vertical, tolerated by each stack before the top container fell from the stack. As a practical matter, the falling of one container was generally accompanied by toppling of the entire stack. TABLE 1 Comparison of Degrees from Vertical Tolerated by the Stack Indicated Control Containers: Stackable Containers: Number/Stack Empty Filled Empty Filled 2 15 20 30 35 3 12 15 25 28 4 9 10 17 22

[0052] As can be readily seen from the data of Table 1, a stack of “stackable containers” according to the invention had a significantly a greater resistance to toppling when tilted than a stack of “control containers” whether empty of filled with water. Such improved stackability is clearly advantageous to retailers in general and grocers in particular.

[0053] It is understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of the present invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description set forth above but rather that the claims be construed as encompassing all of the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains. 

What is claimed is:
 1. A stackable, heat processable, blow molded, plastic container comprising: a body having top and bottom ends and a tubular sidewall; a dome with a finish having an opening, the dome being connected to the top end of the body, the finish adapted to engage a first closure; and a base connected to the bottom end of the body, the base being contoured to engage a portion of a protrusion on a second closure.
 2. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the protrusion defines a peripheral ring.
 3. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the finish and the first closure threadedly engage each other.
 4. The stackable, heat processable, blow molded, plastic container of claim 1, the second closure further comprising: an outer ring portion; and an inner disc portion, wherein the protrusion is formed on the outer ring portion.
 5. The stackable, heat processable, blow molded, plastic container of claim 1, the second closure further comprising: an outer ring portion; and an inner disc portion, wherein the protrusion is formed on the inner disc portion of the closure.
 6. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the finish and the first closure sealingly engage each other.
 7. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the second closure is a press-fit lid.
 8. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the second closure is attached to a second container.
 9. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the base of the container straddles the protrusion of the second closure.
 10. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the base further comprises: an annular standing ring having an outer portion and an inner portion, the outer portion merging with the substantially cylindrical sidewall; a bottom wall defining a central concavity surrounded by the standing ring; and an annular stacking ring interposed between the inner portion of the annular standing ring and the bottom wall operative to engage the portion of the protrusion of the second closure.
 11. The stackable, heat processable, blow molded, plastic container of claim 10, wherein the annular stacking ring has outer and inner walls, the stacking ring being more elevated at the outer wall.
 12. The stackable, heat processable, blow molded, plastic container of claim 11, wherein the annular stacking ring angles downward from the outer wall towards the inner wall.
 13. The stackable, heat processable, blow molded, plastic container of claim 12, wherein the angle from the outer wall to the inner wall is between 1 and 15 degrees from horizontal.
 14. The stackable, heat processable, blow molded plastic container of claim 13 wherein the angle from the outer wall to the inner wall is approximately 7 degrees from horizontal.
 15. The stackable, heat processable, blow molded, plastic container of claim 10, wherein the bottom wall of the base further comprises: a plurality of external ribs having an external rib base disposed upwardly into the central concavity and an external rib apex disposed downwardly towards the stacking ring.
 16. The stackable, heat processable, blow molded, plastic container of claim 10, wherein the annular stacking ring has a shape in radial cross-section which is one of square, rectangular, triangular, frustoconical, semi-circular, and semi-circular.
 17. The stackable, heat processable, blow molded, plastic container of claim 16, wherein the protrusion of the second closure has a shape in radial cross-section which is one of square, rectangular, triangular, frustoconical, semi-circular, and semi-circular.
 18. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the body comprises: a pair of flex panels for accommodating internal changes in pressure and volume in the container, the panels being disposed opposite one another in the body and each panel being planar.
 19. The stackable, heat processable, blow molded, plastic container of claim 1, wherein the opening of the finish has a diameter that is smaller than a width of the body.
 20. The stackable, heat processable, blow molded, plastic container of claim 1, further comprising ribs in the sidewall.
 21. The stackable, heat processable, blow molded container of claim 1, wherein the first and second closures are identical.
 22. The stackable, heat processable, blow molded, plastic container of claim 10, wherein the annular stacking ring has a diameter that is less than a width of the body.
 23. A stack of heat processable, blow molded, plastic containers comprising: a first container having a body having top and bottom ends and a tubular sidewall, a dome with a finish having an opening, the dome being connected to the top end of the body, and a base connected to the bottom end of the body, the base having a stacking ring; and a second container having a body having top and bottom ends and a tubular sidewall, a dome with a finish having an opening, the dome being connected to the top end of the body, a closure having a protrusion and being adapted to engage the finish of the second container, and a base connected to the bottom end of the body, wherein the protrusion of the closure of the second container is adapted to engage the stacking ring of the first container.
 24. The stack of heat processable, blow molded, plastic containers of claim 23, wherein the dome of the second container creates an indentation in the stack such that the base of the first container only makes contact with the closure of the second container.
 25. The stack of heat processable, blow molded, plastic containers of claim 23, wherein the bodies of the first and second containers have different widths.
 26. The stack of heat processable, blow molded, plastic containers of claim 25, wherein the openings of the first and second containers have the same diameter.
 27. The stack of heat processable, blow molded, plastic containers of claim 25, wherein the closures of the first and second containers have the same diameter.
 28. A stackable, blow molded, plastic container comprising: a body having top and bottom ends and a tubular sidewall; a dome with a finish having an opening, the dome being connected to the top end of the body, the finish adapted to engage a first closure; and a base connected to the bottom end of the body, the base being contoured to engage a portion of a protrusion on a second closure, wherein one of the body, dome and base has a distortion resistant structural element.
 29. The stackable, blow molded, plastic container of claim 28, wherein the distortion resistant structural element resists distortion caused by one of hot-fill processing, retort processing and pasteurization.
 30. The stackable, blow molded, plastic container of claim 28 , wherein the base further comprises: an annular standing ring having an outer portion and an inner portion, the outer portion merging with the substantially cylindrical sidewall; a bottom wall defining a central concavity surrounded by the standing ring; and an annular stacking ring interposed between the inner portion of the annular standing ring and the bottom wall operative to engage the portion of the protrusion of the second closure.
 31. The stackable, blow molded, plastic container of claim 30, wherein the distortion resistant structural element resists distortion caused by one of hot-fill processing, retort processing and pasteurization.
 32. A stack of blow molded, plastic containers comprising: a first container having a body having top and bottom ends and a tubular sidewall, a dome with a finish having an opening, the dome being connected to the top end of the body, and a base connected to the bottom end of the body, the base having a stacking ring; and a second container having a body having top and bottom ends and a tubular sidewall, a dome with a finish having an opening, the dome being connected to the top end of the body, a closure having a protrusion and being adapted to engage the finish of the second container, and a base connected to the bottom end of the body, wherein the protrusion of the closure of the second container is adapted to engage the stacking ring of the first container, and one of the dome, body and base of the first container has a distortion resistant structural element.
 33. The stackable, blow molded, plastic container of claim 30, wherein the distortion resistant structural element of the first container comprises means for resisting distortion caused by hot-fill processing of the container.
 34. The stackable, blow molded, plastic container of claim 30, wherein the distortion resistant structural element of the first container comprises means for resisting distortion caused by retort processing of the container.
 35. The stackable, blow molded, plastic container of claim 30, wherein the distortion resistant structural element of the first container comprises means for resisting distortion caused by pasteurization.
 36. A method of manufacturing a plastic container adapted for use with a selected heating process comprising: providing a body having top and bottom ends and a tubular sidewall; providing a dome with a finish having an opening, the dome being connected to the top end of the body, the finish adapted to engage a first closure; and providing a base connected to the bottom end of the body, the base having a stacking ring contoured to engage a portion of a protrusion on a second closure.
 37. The method of claim 36, wherein the selected heating process comprises hot-fill processing.
 38. The method of claim 36, wherein the selected heating process comprises retort processing.
 39. The method of claim 36, wherein the selected heating process comprises pasteurization. 